1. Field of the Invention
The invention relates to a handheld tool for carrying out at least the screwing/unscrewing and/or percussion operations on assembling means, such as screws, bolts or pins.
The percussion operations can be boring, marking or still punching.
2. Description of Related Art Including Information Disclosed Under 37 CFR 1.97 and 37 CFR 1.98.
Different types of screwdrivers capable of driving the screw in rotation are known for disassembling screws. When the screws have remained in place for a long time and/or when the screws are exposed to a corrosive or oxidising environment, the frictions between the thread of the screws and the internal screw thread of the orifices in which they have been placed to oppose a resisting torque which is too high to be overcome by the simple screwing torque.
In this case, a device adapted to large screws, known as impact screwdriver, is well-known, which operates with the strike of a hammer. An internal mechanism of the device transforms the shock into a rotational movement, thereby pressing the insert of the device tight against the impression of the screw, which avoids any risk of slippage. However, such device proves ill-suited for small screws.
In this context, document FR 2,720,024, or still document FR 2,764,226, disclose a handheld tool suitable for loosening small screws. This tool looks like a multipurpose screwdriver with a handle and a tool-carrier rod, in particular terminated by an insert-carrier and comprises an integrated percussion mechanism.
According to the screw to be disassembled, the operator fits the insert with the most suitable impression on the tool, then grabs the tool by its handle and locates the insert in the impression of the screw to be disassembled. To achieve the shock, he only needs to press the handle in the direction of the screw.
During this action, the tool-carrier rod penetrates in the body of the handle while compressing, via a stemming rod, a lead against a trigger spring, thereby causing the compression mechanism to arm. At the end of travel, a cam breaks up the stemming effect of the rod, thereby releasing the trigger spring which propels the lead suddenly against the inner end of the tool-carrier rod, and the shock is generated.
Document FR 2,764,226 discloses more particularly such a tool equipped, additionally, with selection means enabling to block or not the translation of the tool-carrier rod relative to the handle, so as to use the tool as a striking pin or still as a simple screwdriver.
The aim of the present invention is to provide such a tool, for disassembling assembling means, enabling in particular to disassemble small screws, with improved performance.
More particularly, the aim of the present invention is to provide a handheld tool with better transmission of the shock on the surface to be struck during percussion.
Another aim of the invention is to provide a tool whose structure enables one to dissociate the various functions such as, on the one hand, arming and unscrewing, and on the other hand, generation and transmission of shocks, for increased efficiency of the latter.
Another aim of the invention is to provide a percussion tool whose generated shock is not or practically not felt by the operator.
Another aim of the invention is to provide a handheld tool whose percussion shock intensity can be adjusted.
Another aim of the invention is to provide a tool authorizing, not only a percussion function, but also a screwing and/or unscrewing function.
Other aims and advantages of the present invention will appear in the following description which is given only by way of example and without being limited thereto.